Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Onychomycosis usually does not cause any symptoms unless the nail becomes so thick it causes pain when wearing shoes. People with onychomycosis usually go to the doctor for cosmetic reasons, not because of physical pain or problems related to onychomycosis.
As the nail thickens, onychomycosis may interfere with standing, walking, and exercising.
Paresthesia (a sensation of pricking, tingling, or creeping on the skin having no objective cause and usually associated with injury or irritation of a nerve), pain, discomfort, and loss of agility (dexterity) may occur. Loss of self-esteem,
embarrassment, and social problems can also develop.
Severe cases of Candida infections can disfigure the fingertips and nails.
Picture of onychomycosis on the big toes; SOURCE: CDC/Dr. Edwin P. Ewing, Jr.
or signs (appearances) of onychomycosis based on subtype
Onychomycosis is divided into subtypes that can be identified based on where the infection appears to be located relative to the structure of the nail.
In distal lateral subungual onychomycosis (DLSO), the nail plate is thick with a cloudy appearance (opaque), the nail bed underneath the nail thickens and hardens (nail bed hyperkeratosis), and the nail separates from the bed underneath (onycholysis). The nail can be discolored and appear in a range from white to brown. The edge of the nail becomes severely eroded.
In endonyx onychomycosis (EO), the nail plate has a milky white discoloration, but unlike DLSO, the nail does not separate from the bed (no onycholysis). The area under the nail (subungual area) does not thicken or harden (no hyperkeratosis).
White superficial onychomycosis (WSO) is usually confined to the toenails. Small white speckled or powdery-looking patches appear on the surface of the nail plate. The nail becomes rough and crumbles easily.
In proximal subungual onychomycosis (PSO), an area of white spotting, streaking, or discoloration (leukonychia) develops near the nail fold and may extend to deeper layers of the nail. The nail plate becomes white near the cuticle and remains normal at the end.
In total dystrophic onychomycosis, the nail is thickened, opaque, and yellow-brown. The entire nail plate and matrix are affected.
Yeast infection (Candida albicans), while affecting the nail, can appear with additional signs. Candidal infection can occur in the toenails and the fingernails but may also infect the tissue that surrounds the nail. The nail fold becomes inflamed (erythematous), or the nail plate separates from its bed (onycholysis). The nail bed thickens and hardens (nail bed hyperkeratosis), and inflammation of the nail fold is observed in chronic mucocutaneous disease (disease of mucous membrane and regular skin). The affected fingers or toes start to look rounded on the ends, like drumsticks, and, sometimes, the entire thickness of the nail becomes infected.